Spline shaft



' June 1 1926. 1,586,990

H. P. HARRISON SPLINE SHAFT Filed Apri'l 22, 1924 3 I N VEN TOR.

' -2 BY '%%/w A TTORNEY-S Patented June 1, 1926.

UNITED HENRY 1?. HARRISON, OF SYRACUSE, NEW YORK.

SPLINE SHAFT.

Application filed April 22, 1924. Serial No. 708,281.

' embodying my invention.

Figure 2 is a large cross sectional view of such spline shaft.

In forn'iing' spline shafts for mechanism in which extreme accuracy isrequired so as to avoid looseness between the spline shaft and thewheel, gear, clutch section, etc., mounted on the spline shaft, such asspline shafts used in the transmission gears, rear axles of automobiles,etc., the shafts have been cut with the splines thereon and the sides ofthe splines relieved with a suitable tool as a hob and thereafter theshafts ground. The grinding of the splines, in order to accurately fitthe bore of the wheel or hub is a comparatively expensive precisionoperation. In this spline shaft and by this method, the grindingoperation is dispensed with and the splines accurately formed and hencethe liability of developing inaccuracy by unskilled or lack of extremeattention during the grinding operation is avoided.

In the drawings, 1 designates the spline shaft which is shown as formedwith a plui'ality of splines 2 which are cut from the shaft in the usualmanner. The shaft is formed with a groove 3 at the corner of each side4- of the spline and the bottom 5 of the space between the splines. thisgroove extending diagonally inwardlyat the corner of each side 4 andbottom 5, that is, at the base of the spline and inwardly toward thecentral plane of the spline. The groove is usually rectangular in crosssection, and the sides thereof are arranged at an inclined angle to thesides 4. of the splines and the bottom 5 of the space between thesplines, although the groove is not necessarily rectan" gular.

Usually the median plane of the groove in the direction of its depthsubstantially other side of the groove opens through the bottom of thespace between the splines, al though it is not necessary that the grooveopen through the bottom of the space between. the splines, in order torelieve the side of the splines.

l-leretofore, the splines have been relieved by a bobbing operationwhich cuts the splines and the bottom of the space between the splines,as indicated by the dotted lines 6, Fi 2, and thereafter the'splines areaccriately ground by a grinding; wheel.

This spline shaft construction, as described, requires no grinding, thecost of production is considerably less than the spline shafts which areground. and accuracy is obtained without grinding and the liability ofdeveloping inaccuracy is avoided during the grinding operation due tovariations developing in the grinder and variations due to unskilledgrinding or lapses on the part of the workman.

What- I claim is:

1. A splined shaft formed with grooves at the corners of the sides ofthe spline and the bottom of the space between the splines of suchgroove.

2. A splined shaft formed with an inwardly and laterally extendinggroove along the base of each side of the spline.

3. A splined shaft formed with laterally and obliquely extending groovesat the bases of the splines, such grooves openingthrough the sides ofthe splines and the bottom of the space between the splines.

In testimony whereof, I have hereunto signed my name, at Syracuse, inthe county of Onondaga, and State of New York, this 16th day of January19%.

HENRY P. HARRISON.

